How to determine whether a PC has a clean or upgraded installation of Windows 10

Have you ever wondered if you are running an upgrade or clean install of Windows 10? In this guide we will show you how to tell.

Windows has received many releases over the years, and if you had the same computer for a long time, you probably went through a lot of upgrades.

If you're ever curious to see the upgrade history that led to the latest version of your system, Windows 10 does not disclose such information. However, you can use the registry to accurately determine whether you are running an upgrade or clean installation of Windows 10 and how many times a new version of the operating system is installed.

In this Windows 10 Guide we review the steps to use the registry (without having to change anything) to check what type of installation you have. In addition, we help you answer other questions, such as Where was the original version installed on your device and how times an upgrade was applied with the exact date.

How to check Windows installation information

To determine if your device is running a clean or upgrade installer of Windows 10, use the registry with these instructions:

After completing the steps, you will receive the answers to a number of questions:

Does your PC have a clean or upgraded installation of Windows 10?

Within Setup you will find a number of keys (folders). If you see the Upgrade button, your installation is an upgrade. This key could have been created during an upgrade process from a previous version such as Windows 8.1 or Windows 7 or under a Windows Update Feature Update.

Otherwise, if the Upgrade key does not exist, run a clean install of Windows 10.

What was the original version of Windows installed on your PC?

If your installation is an upgrade, you can find out which original version was installed on your device or at least the oldest upgrade since the last clean installation.

Next to the Upgrade key, you will also see one or more Source OS keys corresponding to each upgrade your device went through. You can navigate each key to determine the version (such as Windows 10, Windows 8.1, and Windows 7) that you upgraded from by viewing ProductName String.

You can also determine each feature update that was used for Windows 10 by looking at ReleaseId String. For example, if you run Creators Update one of the Source OS keys must contain a string with the value 1703 . In addition, you may find a key if you refer to 1607 if you at any time installed anniversary update and 1511 to November Update .

When an upgrade was used for your PC?

You have probably noticed that each Source OS key also has a timestamp, this indicates exactly when the installation took place.

This could be valuable information that may be useful in many scenarios. For example, if you If you're experiencing a problem, knowing exactly when your device was upgraded, you can specify a compatibility issue with the newer version.

How to keep track of Windows Insider Preview builds

If you have a computer enrolled in the Windows Insider application, you can also track information about each building used for your system.

The Setup key lets you quickly determine what times a Windows 10 Insider Preview was installed on your device. Additionally, in all Source OS key, you can check other information, such as. The full name of build, build number and version by looking at BuildLab CurrentBuildNumber and ReleaseId Strings.

While you can quickly determine the current version you are driving by comparing the time stamp in the keys, the version you are currently running will also be displayed within Upgrade .